More families who have relatives living in close proximity to them are becoming more curious about a new breed of adjoining studio apartments termed ‘dual-key’ apartments.

In a dual-key home, the studio unit is equipped with a kitchen and bathroom. Its entrance is separate from that of the main unit, both of which open to a shared foyer.

For families with elderly parents to take care of, these adjoining units permit a close watch on them while maintaining privacy. Of course, another reason for the blossoming interest in dual-key apartments is the higher chance of getting the green light to rent out the extra unit.

These dual-key units are offered at some executive condominiums (ECs). EC owners are subject to a minimum occupation period (MOP) of five years, during which they are not allowed to rent out their whole unit. However with dual-key apartments, owners are allowed to rent out the studio unit as long as rules are adhered to.

Speaking to The Straits Times, the Housing Development Board explained that private developers of dual-key apartments market such homes as a single apartment under one strata title – meaning they consider the studio unit a room instead of a separate unit. The Board said these owners still have to comply with subletting conditions, one of which is living in the unit during the lease period.

Already, property consultants say they have received queries from buyers wanting to know if they can sublet the entire studio unit of dual-key homes. Said chief executive of PropNex Mohamed Ismail, “We’ve had an average of five inquiries per week over the last two to three months from people who attended our investment seminars or who approached our agency directly.”

Commenting on the surge in buyer interest, director of research and advisory at Colliers International Chia Siew Chuin said, “Certainly they will be popular. Not only will the landlord be able to rent his extra space, he’ll be able to monitor what his tenant is up to while maintaining privacy for himself and his tenant.” Ismail also said that the flexibility that such units bring will make it especially appealing to younger couples. “Aside from renting it out, they can also break down the walls and transform it when their families expand. Or retain the walls and move their parents in.”

As dual-key homes are a recent addition to the EC market they make up but a small percentage of a project’s total apartment mix, and consultants say numbers are limited. For instance, out of a total of 573 units that make up Esparina Residences (launched last year by Frasers Centrepoint), only 71 of them were dual-key units of various sizes. Similarly, Hoi Hup Realty’s recently launched Tampines project Arc has 574 homes consisting of 64 dual-key apartments. Meanwhile, home-hunters will only be able to get a taste of life in this new type of public housing when the first dual-key EC units reach completion in an estimated three years’ time.

Head of South-east Asia research at Jones Lang LaSalle Chua Yang Liang expects that rental of such homes will be higher than that of individually-rented rooms, but lower or comparable to that of stand-alone studio apartments.